A Yorkshire Building Society Group spokesman said: “To help make the transition as smooth as possible, the 28 Norwich and Peterborough branch closures we announced earlier this year will be made in four phases, between September and December.

“This approach, which ensures closures are spread geographically across the region, is designed to minimise the impact on customers and ensure we maintain the high standards of service our members expect.

“We will be writing to all branch customers to ensure they will be informed of the relevant dates.”

Under the Yorkshire Building Society brand, the group will have a high-street network of 260 branches and agencies.

The plans, unveiled in January, also included the closure of approximately 100,000 N&P current accounts.

Customers initially reacted angrily to the fact N&P was not a member of the seven-day current account switching service, meaning they faced losing out on incentives offered by other banks. However, many have since flexed their guidelines in the hope of attracting new customers from N&P.